1. Field of the Invention
This application relates to water and wastewater treatment operations. More particularly, it concerns improved systems and methods for the handling and transfer of sludge generated in water and wastewater treatment operations.
2. Description of the Prior Art
Large quantities of sludge are created daily in the treatment of water and wastewater. Accordingly, a constant problem exists in the handling and utilization and/or disposal of such sludge. By way of example of the problem, reference is made to a water clarifier system marketed by the assignee of this invention under the trademark DensaDeg.RTM. in which settled solids (sludge) must be transferred from a clarifier back into an upstream reactor. The DensaDeg.RTM. systems are disclosed in an Infilco Degremont Inc. brochure DB-555 entitled DensaDeg.RTM. High Rate Clarifier and Thickener, dated March 1990, the contents of which are incorporated herein by reference.
In the operation of the DensaDeg.RTM. systems, substantially large quantities of fluid sludge must be recycled for chemical reactions to go to completion. Typically, such recycle transfer is accomplished by the use of external, mechanical pumps. Other water or wastewater treatment operations exist in which solids collected as stratified entities must be transferred from one chamber to another, e.g., biological treatment systems wherein biological floc is recycled back from a clarifier to a biological contractor (activated sludge treatment). Hence, the term sludge as used in this disclosure and the accompanying claims is intended to cover not only water treatment sludge per se, but equivalent fluid solid material stratified layers that are transferred from one chamber to another in water and wastewater treatment operations.
The present invention provides unique arrangements and methods for meeting these sludge transfer requirements while greatly reducing the cost of the previously know equipment and energy demands.